People seem to have a love-hate relationship with Harbor Freight, and it mostly seems that they love to hate the purveyor of discount tools. This is not without cause — any number of HF tools have fallen apart in our hands. But there are some gems to be found amid the dregs and dross of your local branch of the 700-store US chain, as long as you match the tool to your needs and manage your expectations.
Now, we’d normally shy away from any electric chainsaw, especially a cordless saw, and doubly so a Harbor Freight special. But as [Professor Charles] demonstrates with his detailed and humorous teardown, the Lynxx 40-volt cordless 14″ chainsaw might be worth picking up just for harvesting parts. First there’s the battery pack, which is chock full of 18650 lithium cells. [Professor Charles] leads us on a detailed tour of the design compromises of the battery and charger and is none too impressed with either, but he clearly understands what it means to build to a price point. While [Charles] found the stock motor controller somewhat anemic, the real buried treasure in the tool is a huge brushless motor, powerful enough to “throw an 8-inch Vise Grip at you” during a (not so) locked rotor test.
The whole teardown is enlightening as to the engineering decisions that go into mass-market tools, so even if you can’t think of something to do with this motor, the article is worth a read. At $169 for the Lynxx (before the 20% coupon in your Sunday paper every week) it’s a little pricey to buy just to harvest parts, but it wouldn’t be the first HF tool to suffer that fate. We’ll bet these things will start showing up broken on the secondary market for a song, and if the [Professor]’s assessments are right, it likely won’t be the motors that fail.
[thelostspore] was experimenting with resin casting, and discovered that he needed a pressure casting chamber in order to get clear casts. There are commercial solutions for sale, and they are really nice. However, many hackers are on a budget, and if you’re only casting every now and then you don’t need such a fancy set-up.
Re-purposing equipment like this is pretty common in the replica prop making community. Professional painters use a pressurized pot filled with paint to deliver to their spray guns. These pots can take 60-80 PSI and are built to live on a job site. By re-arranging some of the parts you can easily get a chamber that can hold 60 PSI for enough hours to successfully cast a part. Many import stores sell a cheap version, usually a bit smaller and with a sub-par gasket for around 80 US Dollars. [thelostspore] purchased one of these, removed the feed tube from lid and plugged the outlet. He then attached a quick release fitting to the inlet of the regulator.
We used this guide to build our own pressure casting set-up. Rather than plug up the outlet on ours, we put a ball valve with a muffler in its place to quickly and safely vent the chamber when the casting has set. We recommend putting a female quick connect coupling or another ball valve in combination with the male fitting (if your hose end is female). It is not super dangerous to do it the way the guide recommends, but this is safer, and you can disconnect the compressor from the tank without losing pressure.
All that was left was to test it. He poured an identical mold and it came out clear!
The speed controller is a $20 unit from Harbor Freight. It comes with an On/Off switch and knob which adjusts the power going to the router. [Jesse] pulled off the knob and milled a gear which takes its place. The second gear is attached to the horn of a hobby servo mounted on the side of the speed controller. The video after the break demonstrates an Arduino driving the servo based on a potentiometer input as well as commands from the CNC controller board he’s using.
Design files for the gears and the Arduino code which drives the servo is available from his Github repository.
[Zitt] is sharing some methods he’s honed for color-matching powder coat paint. He developed these techniques while restoring a 1982 Star Trek coin-op machine. The image above shows a paddle used for the game. The plate that houses the control was beat up, and he needed to repaint it but wanted to make sure it didn’t look out-of-place with the molded plastic that surrounds it.
He gets his powder paints from Harbor Freight, a favorite depot for hackable goods (like drill motors, or metal carts). Usually these paints would be applied by attracting them to the piece using electrostatic charges. [Zitt’s] not doing that, but applying them with a paint sprayer instead.
The first step is to match your color. He’s using an electronic color matching device which gives data to plug into a chart on the web for a color match. Once you’ve got a formula, mix up the powder coat, and then dissolve it into some Methyl Ethyl Ketone. This goes into the spray gun and is applied in an even coat. Before heading into an oven for curing, it’s important to wait for this coat to dry. [Zitt] observed some boiling MEK on a wet test piece that left an undesirable texture on the baked paint after curing. After running a few test pieces he picked the blend that was the best match and then painted all of his restored parts.
[Rob] just finished reinforcing a cheap drill motor. He picked up the tool at Harbor Freight and ditched the case. The plastic retaining ring was replaced with a thick metal washer which he machine The washer uses three bolts to attach to the mounting plate that he welded together. We’re not exactly sure what he’s got in mind as he only mentioned that this will be used with a robot. We wouldn’t mind having one of these as a bench motor but there must be hundreds of uses now that it can be attached to just about anything. It seems Harbor Freight has become popular as hacking’s raw material source. The last example we saw of this was a welding table made from a utility cart.
[Todd Harrison] put together a welding cart that has all kinds of tricks built-in. The carcass is a cheap rolling cart that has been reinforced with steel plate and beefier wheels. The top tray can be loaded up with fire brick for oxygen-acetylene welding or with a grate for cutting. That grate lets the slag fall through and into the red-rimmed fire-box below. Finally, there’s a steel plate to the right of the cart that rotates and slides over the top of the unit to prepare it for MIG welding. Todd walks us through his versatile invention in the video after the break. This will nicely augment your other welding hacks.
[Mikey] looks at a model from ebay, Harbor Freight, and Radio Shack. Not surprisingly, the ebay offering doesn’t rate too well but does get the job done. We were surprised to read that he picked up the Cen-Tech model for about $10 at Harbor Freight. Although it may no longer be sold there (we haven’t checked) [Mikey] seems pretty happy with it so we’ll be on the lookout during our next tool-buying trip. We’re unfamiliar with the tiny Radio Shack 22-820 but we’ve always been happy with our larger 22-811. The 22-820 allows the probes to be folded up inside of the case cover for a truly pocketable package.
You can never have too many meters at your disposal and we’ll have to keep this article in mind the next time we’re shopping for another. Never used a multimeter before? Take a look at the tutorial [Mikey] linked to over at ladyada.